Make imgui scale factor aware

Closes #74

plugins/Cardinal/src/DearImGui/imgui_impl_opengl2.cpp

@@ -125,7 +125,7 @@ static void ImGui_ImplOpenGL2_SetupRenderState(ImDrawData* draw_data, int fb_wid
     glShadeModel(GL_SMOOTH);
     glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 
-#ifndef IMGUI_DPF_BACKEND
+#if 0 // ndef IMGUI_DPF_BACKEND
     // If you are using this code with non-legacy OpenGL header/contexts (which you should not, prefer using imgui_impl_opengl3.cpp!!),
     // you may need to backup/reset/restore other state, e.g. for current shader using the commented lines below.
     // (DO NOT MODIFY THIS FILE! Add the code in your calling function)

plugins/Cardinal/src/Ildaeil.cpp

@@ -1267,16 +1267,17 @@ struct IldaeilWidget : ImGuiWidget, IdleCallback, Thread {
 
     void drawError(const bool open)
     {
+        const float scaleFactor = getScaleFactor();
+
         ImGui::SetNextWindowPos(ImVec2(0, 0));
-        ImGui::SetNextWindowSize(ImVec2(box.size.x, box.size.y));
+        ImGui::SetNextWindowSize(ImVec2(box.size.x * scaleFactor, box.size.y * scaleFactor));
 
         const int flags = ImGuiWindowFlags_NoSavedSettings
                         | ImGuiWindowFlags_NoTitleBar
                         | ImGuiWindowFlags_NoResize
                         | ImGuiWindowFlags_NoCollapse
                         | ImGuiWindowFlags_NoScrollbar
-                        | ImGuiWindowFlags_NoScrollWithMouse
+                        | ImGuiWindowFlags_NoScrollWithMouse;
-                        | ImGuiWindowFlags_NoCollapse;
 
         if (ImGui::Begin("Error Window", nullptr, flags))
         {
@@ -1288,7 +1289,6 @@ struct IldaeilWidget : ImGuiWidget, IdleCallback, Thread {
                              | ImGuiWindowFlags_NoCollapse
                              | ImGuiWindowFlags_NoScrollbar
                              | ImGuiWindowFlags_NoScrollWithMouse
-                             | ImGuiWindowFlags_NoCollapse
                              | ImGuiWindowFlags_AlwaysAutoResize
                              | ImGuiWindowFlags_AlwaysUseWindowPadding;
 
@@ -1304,18 +1304,18 @@ struct IldaeilWidget : ImGuiWidget, IdleCallback, Thread {
 
     void drawTopBar()
     {
+        const float scaleFactor = getScaleFactor();
         const float padding = ImGui::GetStyle().WindowPadding.y * 2;
 
         ImGui::SetNextWindowPos(ImVec2(0, 0));
-        ImGui::SetNextWindowSize(ImVec2(box.size.x, kButtonHeight + padding));
+        ImGui::SetNextWindowSize(ImVec2(box.size.x * scaleFactor, kButtonHeight * scaleFactor + padding));
 
         const int flags = ImGuiWindowFlags_NoSavedSettings
                         | ImGuiWindowFlags_NoTitleBar
                         | ImGuiWindowFlags_NoResize
                         | ImGuiWindowFlags_NoCollapse
                         | ImGuiWindowFlags_NoScrollbar
-                        | ImGuiWindowFlags_NoScrollWithMouse
+                        | ImGuiWindowFlags_NoScrollWithMouse;
-                        | ImGuiWindowFlags_NoCollapse;
 
         if (ImGui::Begin("Current Plugin", nullptr, flags))
         {
@@ -1344,17 +1344,20 @@ struct IldaeilWidget : ImGuiWidget, IdleCallback, Thread {
 
     void setupMainWindowPos()
     {
+        const float scaleFactor = getScaleFactor();
+
         float y = 0;
-        float height = box.size.y;
+        float width = box.size.x * scaleFactor;
+        float height = box.size.y * scaleFactor;
 
         if (fDrawingState == kDrawingPluginGenericUI)
         {
-            y = kButtonHeight + ImGui::GetStyle().WindowPadding.y * 2 - 1;
+            y = kButtonHeight * scaleFactor + ImGui::GetStyle().WindowPadding.y * 2 - scaleFactor;
             height -= y;
         }
 
         ImGui::SetNextWindowPos(ImVec2(0, y));
-        ImGui::SetNextWindowSize(ImVec2(box.size.x, height));
+        ImGui::SetNextWindowSize(ImVec2(width, height));
     }
 
     void drawGenericUI()
@@ -1364,9 +1367,12 @@ struct IldaeilWidget : ImGuiWidget, IdleCallback, Thread {
         PluginGenericUI* const ui = fPluginGenericUI;
         DISTRHO_SAFE_ASSERT_RETURN(ui != nullptr,);
 
-        // ImGui::SetNextWindowFocus();
+        const int pflags = ImGuiWindowFlags_NoSavedSettings
+                         | ImGuiWindowFlags_NoResize
+                         | ImGuiWindowFlags_NoCollapse
+                         | ImGuiWindowFlags_AlwaysAutoResize;
 
-        if (ImGui::Begin(ui->title, nullptr, ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoCollapse))
+        if (ImGui::Begin(ui->title, nullptr, pflags))
         {
             const CarlaHostHandle handle = module->fCarlaHostHandle;
 
@@ -1452,9 +1458,7 @@ struct IldaeilWidget : ImGuiWidget, IdleCallback, Thread {
                              | ImGuiWindowFlags_NoCollapse
                              | ImGuiWindowFlags_NoScrollbar
                              | ImGuiWindowFlags_NoScrollWithMouse
-                             | ImGuiWindowFlags_NoCollapse
+                             | ImGuiWindowFlags_AlwaysAutoResize;
-                             | ImGuiWindowFlags_AlwaysAutoResize
-                             | ImGuiWindowFlags_AlwaysUseWindowPadding;
 
             if (ImGui::BeginPopupModal("Plugin Error", nullptr, pflags))
             {
@@ -1643,8 +1647,8 @@ struct IldaeilModuleWidget : ModuleWidget {
         if (module != nullptr && module->pcontext != nullptr)
         {
             ildaeilWidget = new IldaeilWidget(module);
-            ildaeilWidget->box.pos = Vec(2 * RACK_GRID_WIDTH, 0);
+            ildaeilWidget->box.pos = Vec(2 * RACK_GRID_WIDTH, 1);
-            ildaeilWidget->box.size = Vec(box.size.x - 2 * RACK_GRID_WIDTH, box.size.y);
+            ildaeilWidget->box.size = Vec(box.size.x - 2 * RACK_GRID_WIDTH - 1, box.size.y - 2);
             addChild(ildaeilWidget);
         }
 

plugins/Cardinal/src/ImGuiTextEditor.cpp

@@ -131,8 +131,10 @@ std::string ImGuiTextEditor::getCurrentLineText()const
 
 void ImGuiTextEditor::drawImGui()
 {
+    const float scaleFactor = getScaleFactor();
+
     ImGui::SetNextWindowPos(ImVec2(0, 0));
-    ImGui::SetNextWindowSize(ImVec2(box.size.x, box.size.y));
+    ImGui::SetNextWindowSize(ImVec2(box.size.x * scaleFactor, box.size.y * scaleFactor));
 
     if (ImGui::Begin("TextEdit", nullptr, ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize))
     {

plugins/Cardinal/src/ImGuiWidget.cpp

@@ -27,8 +27,11 @@
 struct ImGuiWidget::PrivateData {
     ImGuiContext* context = nullptr;
     bool created = false;
+    bool fontGenerated = false;
+    float originalScaleFactor = 0.0f;
+    float scaleFactor = 0.0f;
 
-    PrivateData(const double scaleFactor = 1.0)
+    PrivateData()
     {
         IMGUI_CHECKVERSION();
         context = ImGui::CreateContext();
@@ -38,45 +41,6 @@ struct ImGuiWidget::PrivateData {
         io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;
         io.IniFilename = nullptr;
 
-        ImGuiStyle& style(ImGui::GetStyle());
-        style.FrameRounding = 4;
-        /*
-        style.ScaleAllSizes(scaleFactor);
-        */
-
-        const ImVec4 color_Cardinal(0.76f, 0.11f, 0.22f, 1.00f);
-        const ImVec4 color_DimCardinal(171.0 / 255.0, 54.0 / 255.0, 73.0 / 255.0, 1.00f);
-
-        ImVec4* const colors = style.Colors;
-        colors[ImGuiCol_Text]             = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
-        colors[ImGuiCol_TextDisabled]     = ImVec4(0.50f, 0.50f, 0.50f, 1.00f);
-        colors[ImGuiCol_WindowBg]         = ImVec4(0.101f, 0.101f, 0.101f, 0.94f);
-        colors[ImGuiCol_FrameBg]          = ImVec4(0.20f, 0.21f, 0.22f, 0.54f);
-        colors[ImGuiCol_FrameBgHovered]   = ImVec4(0.40f, 0.40f, 0.40f, 0.40f);
-        colors[ImGuiCol_FrameBgActive]    = ImVec4(0.18f, 0.18f, 0.18f, 0.67f);
-        colors[ImGuiCol_TitleBgActive]    = ImVec4(0.29f, 0.29f, 0.29f, 1.00f);
-        colors[ImGuiCol_CheckMark]        = color_Cardinal;
-        colors[ImGuiCol_SliderGrab]       = color_DimCardinal;
-        colors[ImGuiCol_SliderGrabActive] = color_Cardinal;
-        colors[ImGuiCol_Button]           = color_DimCardinal;
-        colors[ImGuiCol_ButtonHovered]    = color_Cardinal;
-        colors[ImGuiCol_ButtonActive]     = color_Cardinal;
-        colors[ImGuiCol_TextSelectedBg]   = ImVec4(0.87f, 0.87f, 0.87f, 0.35f);
-        colors[ImGuiCol_Header]           = ImVec4(0.44f, 0.44f, 0.44f, 0.40f);
-        colors[ImGuiCol_HeaderHovered]    = color_DimCardinal;
-        colors[ImGuiCol_HeaderActive]     = color_Cardinal;
-
-#ifndef DGL_NO_SHARED_RESOURCES
-        using namespace dpf_resources;
-        ImFontConfig fc;
-        fc.FontDataOwnedByAtlas = false;
-        fc.OversampleH = 1;
-        fc.OversampleV = 1;
-        fc.PixelSnapH = true;
-        io.Fonts->AddFontFromMemoryTTF((void*)dejavusans_ttf, dejavusans_ttf_size, 13.0f * scaleFactor, &fc);
-        io.Fonts->Build();
-#endif
-
         io.KeyMap[ImGuiKey_Tab] = GLFW_KEY_TAB;
         io.KeyMap[ImGuiKey_LeftArrow] = GLFW_KEY_LEFT;
         io.KeyMap[ImGuiKey_RightArrow] = GLFW_KEY_RIGHT;
@@ -112,6 +76,58 @@ struct ImGuiWidget::PrivateData {
 
         ImGui::DestroyContext(context);
     }
+
+    void generateFontIfNeeded()
+    {
+        if (fontGenerated)
+            return;
+
+        DISTRHO_SAFE_ASSERT_RETURN(scaleFactor != 0.0f,);
+
+        fontGenerated = true;
+
+#ifndef DGL_NO_SHARED_RESOURCES
+        ImGuiIO& io(ImGui::GetIO());
+        using namespace dpf_resources;
+        ImFontConfig fc;
+        fc.FontDataOwnedByAtlas = false;
+        fc.OversampleH = 1;
+        fc.OversampleV = 1;
+        fc.PixelSnapH = true;
+        io.Fonts->AddFontFromMemoryTTF((void*)dejavusans_ttf, dejavusans_ttf_size, 13.0f * scaleFactor, &fc);
+        io.Fonts->Build();
+#endif
+    }
+
+    void resetStyle()
+    {
+        ImGuiStyle& style(ImGui::GetStyle());
+
+        style.FrameRounding = 4;
+        style.ScaleAllSizes(scaleFactor);
+
+        const ImVec4 color_Cardinal(0.76f, 0.11f, 0.22f, 1.00f);
+        const ImVec4 color_DimCardinal(171.0 / 255.0, 54.0 / 255.0, 73.0 / 255.0, 1.00f);
+
+        ImVec4* const colors = style.Colors;
+        colors[ImGuiCol_Text]             = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
+        colors[ImGuiCol_TextDisabled]     = ImVec4(0.50f, 0.50f, 0.50f, 1.00f);
+        colors[ImGuiCol_WindowBg]         = ImVec4(0.101f, 0.101f, 0.101f, 0.94f);
+        colors[ImGuiCol_FrameBg]          = ImVec4(0.20f, 0.21f, 0.22f, 0.54f);
+        colors[ImGuiCol_FrameBgHovered]   = ImVec4(0.40f, 0.40f, 0.40f, 0.40f);
+        colors[ImGuiCol_FrameBgActive]    = ImVec4(0.18f, 0.18f, 0.18f, 0.67f);
+        colors[ImGuiCol_TitleBgActive]    = ImVec4(0.29f, 0.29f, 0.29f, 1.00f);
+        colors[ImGuiCol_CheckMark]        = color_Cardinal;
+        colors[ImGuiCol_SliderGrab]       = color_DimCardinal;
+        colors[ImGuiCol_SliderGrabActive] = color_Cardinal;
+        colors[ImGuiCol_Button]           = color_DimCardinal;
+        colors[ImGuiCol_ButtonHovered]    = color_Cardinal;
+        colors[ImGuiCol_ButtonActive]     = color_Cardinal;
+        colors[ImGuiCol_TextSelectedBg]   = ImVec4(0.87f, 0.87f, 0.87f, 0.35f);
+        colors[ImGuiCol_Header]           = ImVec4(0.44f, 0.44f, 0.44f, 0.40f);
+        colors[ImGuiCol_HeaderHovered]    = color_DimCardinal;
+        colors[ImGuiCol_HeaderActive]     = color_Cardinal;
+    }
 };
 
 ImGuiWidget::ImGuiWidget()
@@ -122,6 +138,11 @@ ImGuiWidget::~ImGuiWidget()
     delete imData;
 }
 
+float ImGuiWidget::getScaleFactor() const noexcept
+{
+    return imData->scaleFactor;
+}
+
 void ImGuiWidget::onContextCreate(const ContextCreateEvent& e)
 {
     OpenGlWidget::onContextCreate(e);
@@ -146,13 +167,42 @@ void ImGuiWidget::onContextDestroy(const ContextDestroyEvent& e)
 
 void ImGuiWidget::drawFramebuffer()
 {
-    const math::Vec fbSize = getFramebufferSize();
-
     ImGui::SetCurrentContext(imData->context);
     ImGuiIO& io(ImGui::GetIO());
 
-    io.DisplayFramebufferScale = ImVec2(fbSize.x / box.size.x, fbSize.y / box.size.y);
+    const math::Vec fbSize = getFramebufferSize();
-    io.DisplaySize = ImVec2(box.size.x, box.size.y);
+    const float scaleFactor = APP->window->pixelRatio;
+
+    if (d_isNotEqual(imData->scaleFactor, scaleFactor))
+    {
+        imData->scaleFactor = scaleFactor;
+
+        ImGuiStyle& style(ImGui::GetStyle());
+        new(&style)ImGuiStyle();
+        imData->resetStyle();
+
+        if (! imData->fontGenerated)
+        {
+            imData->originalScaleFactor = scaleFactor;
+            imData->generateFontIfNeeded();
+        }
+        else
+        {
+            io.FontGlobalScale = scaleFactor / imData->originalScaleFactor;
+        }
+    }
+
+    glMatrixMode(GL_PROJECTION);
+    glPushMatrix();
+    glLoadIdentity();
+    glOrtho(0.0, box.size.x * scaleFactor, box.size.y * scaleFactor, 0.0, -1.0, 1.0);
+    glViewport(0.0, 0.0, fbSize.x, fbSize.y);
+    glMatrixMode(GL_MODELVIEW);
+    glPushMatrix();
+    glLoadIdentity();
+
+    io.DisplaySize = ImVec2(box.size.x * scaleFactor, box.size.y * scaleFactor);
+    io.DisplayFramebufferScale = ImVec2(fbSize.x / (box.size.x * scaleFactor), fbSize.y / (box.size.y * scaleFactor));
 
     if (!imData->created)
     {
@@ -180,6 +230,12 @@ void ImGuiWidget::onHover(const HoverEvent& e)
     ImGuiIO& io(ImGui::GetIO());
     io.MousePos.x = e.pos.x + e.mouseDelta.x;
     io.MousePos.y = e.pos.y + e.mouseDelta.y;
+
+    if (d_isNotEqual(imData->scaleFactor, 1.0f))
+    {
+        io.MousePos.x *= imData->scaleFactor;
+        io.MousePos.y *= imData->scaleFactor;
+    }
 }
 
 void ImGuiWidget::onDragHover(const DragHoverEvent& e)
@@ -189,6 +245,12 @@ void ImGuiWidget::onDragHover(const DragHoverEvent& e)
     ImGuiIO& io(ImGui::GetIO());
     io.MousePos.x = e.pos.x + e.mouseDelta.x;
     io.MousePos.y = e.pos.y + e.mouseDelta.y;
+
+    if (d_isNotEqual(imData->scaleFactor, 1.0f))
+    {
+        io.MousePos.x *= imData->scaleFactor;
+        io.MousePos.y *= imData->scaleFactor;
+    }
 }
 
 void ImGuiWidget::onDragLeave(const DragLeaveEvent& e)
@@ -207,9 +269,18 @@ void ImGuiWidget::onHoverScroll(const HoverScrollEvent& e)
 {
     ImGui::SetCurrentContext(imData->context);
 
+    float deltaX = e.scrollDelta.x;
+    float deltaY = e.scrollDelta.y;
+
+    if (d_isNotEqual(imData->scaleFactor, 1.0f))
+    {
+        deltaX *= imData->scaleFactor;
+        deltaY *= imData->scaleFactor;
+    }
+
     ImGuiIO& io(ImGui::GetIO());
-    io.MouseWheel += e.scrollDelta.y * 0.01f;
+    io.MouseWheel += deltaY * 0.01f;
-    io.MouseWheelH += e.scrollDelta.x * 0.01f;
+    io.MouseWheelH += deltaX * 0.01f;
 
     if (io.WantCaptureMouse)
         e.consume(this);

plugins/Cardinal/src/ImGuiWidget.hpp

@@ -34,6 +34,8 @@ struct ImGuiWidget : OpenGlWidget {
         ImGui::ShowDemoWindow();
     }
 
+    float getScaleFactor() const noexcept;
+
 protected:
     void onContextCreate(const ContextCreateEvent& e) override;
     void onContextDestroy(const ContextDestroyEvent& e) override;